MSM7557

E2A0046-16-X1 ¡ Semiconductor ¡ Semiconductor MSM7557 This version: Jan. 1998 MSM7557 Previous version: Nov. 1996 Single Chip MSK Modem with Compandor for Cordless Telephone GENERAL DESCRIPTION The MSM7557 is a single chip MSK modem with base band voice processor for cordless telephone. The MSM7557 voice transmit block consists of high pass filter, compressor, pre-emphasis, limiter and splatter filter. Voice receive block consists of Band pass filter, De-emphasis and Expander. FEATURES Available to transmit modem signal and also transmit base band voice signal through wireless transmission path (0.3 kHz to 3.4 kHz) Built-in compandor circuit Upper limit of voice band (3306 Hz/3400 Hz/3500 Hz) is selectable Modem bit rate (2400/1200 bps) is selectable Transmit function and receive function operate separately Emphasis mode selectable Built-in bit synchronous detector and frame synchronous detector Built-in limiter level generator and external limit voltage input Dynamic range selectable Built-in crystal oscillator circuit Wide range power supply voltage (2.7V ~ 5.5V) Package : 56-pin plastic QFP (QFP56-P-910-0.65-2K) (Product name : MSM7557GS-2K) 1/25 ¡ Semiconductor BLOCK DIAGRAM CMPI CC1 CC2 CC3N CC3P TVIO TVI – LIM Compressor + HPF1 PreEmphasis Limiter Splatter Filter RCLPF TAO SEC DYN TVE ME EMP RCK1 RCK2 RD RT FD FPS BIT FDE CSH SD ST BR VR1 VR2 VR3 BYP VDD GND SG MOD RCLPF DEMOD SG Mix LPF Mixer DEMBPF CONT Flame Det Shaper ...